This invention relates to a novel foldable hand tool for sharpening the cutting edge of knives and the like, being particularly suitable for convenient pocket carrying.
Sharpening hand tools are well known in the prior art, for use in sharpening cutting edges such as the blades of knives and the like cutting instruments.
Pocket sharpening tools, e.g. hand tools which can be comfortably carried in conventional clothing pockets or the like of a user, continue to be desired by the consuming public. Such pocket sharpening tools as may be available, generally comprise a sharpening element such as a small rectilinear composite stone or the like material, that is generally packaged in a pouch or the like for pocket carrying, and which are generally uncomfortable to carry and susceptible to breaking when dropped or subjected to bending forces. The size of the stone is generally small for convenient pocket carrying, which makes the hands-on manipulation of the small stone during the sharpening process generally unsafe for the user and generally reduces the ability to conveniently and accurately sharpen a cutting edge.
It is an object of the present invention to provide a pocket sized sharpening device with protective structure surrounding the sharpening element from breakage.
It is another object of the invention to provide a convenient pocket sized sharpening device comprising a handle for safe hands-on manipulation of the device in association with cutting edges.
It is a further object of the invention to provide a foldable sharpening device, which has convenient means for safely and accurately guiding a cutting edge along a sharpening surface during the sharpening process.
It is a still further object of the invention to provide a portable sharpening device which is convenient and comfortable to carry in conventional pockets of the clothing of a user.
These and other objects of the invention will become apparent in the following recitation of the invention.
The present invention is a foldable hand sharpening tool, generally comprising an elongate body having a first end containing an elongate sharpening means pivotally mounted along a transverse axis, and an opposite end comprising an opposing element sharpening means, with provision for spaced elongate guide members arranged to guide the cutting edge of a blade in planer orientation to the opposing element sharpening means.
The elongate body functions as both a handle and a receptacle for both sharpening means. The body comprises a hollow(s) adjacent the first end for pivotally folding the elongate sharpening means into for storage, the same and/or different hollow(s) for storage of the elongate guide members when not in use, and functions as a handle for hands-on manipulation when either of the sharpening means are in use.
In accordance with the invention, the elongate body of the tool comprises a first end and opposite end with two oppositely disposed elongate sides extending therebetween, a first axle extending transversely between the sides of the body at about the first end of the body and one or more second axles extending transversely between the sides of the body at about the opposite end.
Pivotally mounted on the first transverse axle at the first end of the body is an elongate sharpening means, said means comprising one or more elongate sharpening members having a surface enabled to abrade and/or sharpen a blade of a knife. By pivot mounting of the elongate sharpening means is meant a sharpening member is independently rotatably mounted to about the first end of the body on the first axle similar to pivot mounting of a folding knife blade, or the axle is rotatably mounted to about the first end of the body, in an arrangement such that the elongate sharpening member can be conveniently rotated (folded) into storage in a hollow between the sides of the body and rotated (unfolded) to extend from the body of the tool for sharpening use. The body functioning as a handle extension for manipulating the first sharpening means during use and as a secure storage receptacle when not in use.
The first sharpening means can comprise one or more sharpening members of any suitable elongate shape which comprise any suitable abrading surface. Thus, a sharpening member may be of any convenient elongate shape such as rectilinear, cone, columnar or the like shape suitably sized to be pivot folded into and/or unfolded out from the sides of the body.
Suitable sharpening surfaces for the sharpening members generally include roughened or ridged surfaces, for example a roughened and/or ridge containing metal surface such as a file surface and the like, a sharpening stone or composite material formed from abrading material or the like, or even a member generally formed from a first material such as a metal or plastic and comprising a grit sharpening material thereon such as diamond or hard stone grit or the like sufficient to abrade material from the cutting edge of a knife.
The opposite second end of the elongate body of the invention comprises an opposing element sharpening means. By opposing element sharpening means is meant a sharpening means comprising opposing mounted sharpener elements between which a blade or the like is drawn for sharpening. Preferably, opposing elements are mounted in an arrangement with guide members positioned to maintain the blade of a knife and the like to be sharpened in guided spacial orientation with the opposing sharpener elements.
The opposing elements of the sharpening means are mounted between the sides of the elongate body proximate the second end thereof, in an offset stacked arrangement wherein sharpening edges, surfaces or the like of opposing adjacent stacked elements define a generally xe2x80x9cVxe2x80x9d shaped drawing slot through which the blade of a knife can be slidably drawn to abrade the sides of the knife blade proximate the cutting edge to form a sharpened cutting edge. The sharpener elements are arranged so that orientation of the generally xe2x80x9cVxe2x80x9d shaped drawing slot enables drawing of the blade in a direction generally transverse to the longitudinal axis of the tool, enabling safe positioning of the user""s hands along the body of the tool, adjacent the xe2x80x9cVxe2x80x9d slot, during sharpening.
Sharpener elements of the opposing element sharpening means are generally mounted along adjacent about parallel planes in offset stacked arrangement. In a preferred embodiment, the opposing sharpening elements are arranged about parallel to the longitudinal axis of the elongate body, but it should be understood that such about parallel alignment with the longitudinal axis is not essential.
The sharpener elements may be fixedly, removably or movably mounted to the elongate body. In one embodiment, polygonal sharpener elements having a generally straight sharpening surface along one edge thereof are fixedly offset mounted such that the sharpening edge of each opposing element defines a leg of the generally xe2x80x9cVxe2x80x9d shaped slot. In another embodiment, each polygonal element comprises two or more sharpening edges and the elements are mounted for convenient repositioning so that a different sharpening edge defines a leg. For example, a quadrangular sharpener element is mounted within a mating quadrangular slot arranged in the elongate body so that an exposed edge of the element defines a leg of the xe2x80x9cVxe2x80x9d shaped slot. As the exposed edge of the element wears, the element can be removed and reset in the slot with a fresh edge exposed. Similarly, such element may be removable, adjustably or even rotatably mounted by screw or the like means for convenient repositioning of sharpening edges.
In a still further embodiment, opposing elements comprise rotatable disks mounted to axles along the body of the tool proximate the second end a sharpening edge or circumferential surface of the disks forming a curved, generally xe2x80x9cVxe2x80x9d shaped slot. It should be understood that it is within the contemplation of the invention to use any suitable shape and form of opposing sharpening elements which can be combined to form a generally xe2x80x9cVxe2x80x9d shaped drawing slot for sharpening a blade.
In a preferred embodiment of the invention the sides of the body of the tool surrounding the common transverse cutting axis are slotted to avoid engaging the blade being drawn through the generally xe2x80x9cVxe2x80x9d shaped slot during the sharpening process. Two or more opposing sharpening elements can be arranged on the second end of the body, but generally it is preferred to use only two opposing sharpening elements.
Opposing sharpening elements can generally comprise any suitable roughened or ridged surface, for example a roughened and/or ridge containing metal surface such as a file and the like, a sharpening stone or composite material formed from abrading material or the like, or even a metal element comprising a grit sharpening material thereon and the like. In a preferred embodiment, the elements insert into mounting slots of a mounting block and have hardened sharpening edges which are retained by the slot at a defined angle to form the xe2x80x9cVxe2x80x9d shaped sharpening slot. The elements comprise elongate slots through which screw means adjustably fix their position.
Preferably, elongate guide members are arranged to retain the blade in a defined spacial orientation with the sharpening elements and resist slipping of a blade from the generally xe2x80x9cVxe2x80x9d shaped slot during sharpening.
The guide members generally comprise an elongate member which pivotally or removably mounts to the elongate body. The guide members are arranged to extend from the body of the tool and comprise a surface which supports the blade in a desirable orientation during sharpening. In one embodiment, a guide member comprises a base pin element which screws into or inserts into a hole or slot integral with the body of the tool and a guide cap which provides the surface which guides the blade. In such embodiment, means are generally provided for storage of the caps when not in use, preferably in a hollow or the like of the body of the tool.
In another embodiment the guide member comprises a base pin element which is pivotally connected to the body and guide caps are integral to or removably connected thereto. In a preferred embodiment, the base pin element of a guide member is pivot mounted at about the opposing sharpening means, so that the guide member can be pivoted into a hollow between the sides when not in use. By pivot mounting of the guide member is meant it is rotatably mounted to the body similar to a folding knife blade, such that the guide member can be conveniently rotated or folded into storage along or between the sides of the body and rotated or folded outwardly to extend from the body as appropriate to guide a blade to be sharpened along the generally xe2x80x9cVxe2x80x9d shaped slot.
Generally a guide cap can be concentric or eccentric in relationship to the centerline of the base pin element. In one embodiment, the guide cap is removably mounted to the base end and a selection of varying diameter guide caps are provided for selected concentric attachment to the base pin element to enable adjustment of a guide surface in respect to the centerline of the xe2x80x9cVxe2x80x9d shaped slot. In a further embodiment, a guide cap is eccentrically attached to the base pin element enabling adjustable orientation of a guide surface of the guide pin in respect to the centerline of the xe2x80x9cVxe2x80x9d shaped sharpening slot.